The Worst Hosting Networks (for Spam) – March 2014 Update April 1st, 2014, by ksimpson
Spammers have long used ISP networks to send spam, taking ownership of PCs and mobile devices and using them to send spam. But in recent years, defenses against this type of spamming have improved remarkably, making this type of spamming much less effective and profitable. Not to be deterred, spammers have increased their focus on […]
Why we should all be thankful for Nelson Mandela December 5th, 2013, by admin
Just moments ago, I heard that one of the world’s greatest men has passed – thankfully in peace with his family surrounding him. I was born in South Africa; my family left shortly thereafter, but I continue to have ties to the country through relatives, and had the fortune of visiting there a year ago. […]
Fifty questions for Spamhaus, with our answers March 15th, 2013, by admin
Ken Magill, who writes a weekly marketing blog called “The Magill Report”, recently solicited his readers to submit questions for Steve Linford, principle at Spamhaus. Ken’s readers sent in 51 questions, and I thought it would be fun to take a crack at answering them. Here goes: 1. How can Spamhaus work directly with legitimate […]
World’s largest spam sources are all hosting companies March 1st, 2013, by admin
Over the past twelve months, there has been a dramatic shift in the world’s spam. Whereas twelve months ago, much of the world’s spam originated from botnet-controlled PCs on ISP networks, most of the world’s spam volume now originates from web hosting provider networks. This is an anachronism in many ways, because in the early […]
AOL accidentally rejects millions of messages October 16th, 2012, by admin
AOL started rejecting connections instead of temp-failing them, under certain conditions. This has resulted in a major increase in non-delivery receipts worldwide.
How web hosting providers can battle fraudulent sign-ups October 2nd, 2012, by admin
Spamhaus recently released an excellent guide for hosting providers describing how to avoid signing up fraudulent customers. In this blog post, we summarize Spamhaus’ recommendations.
What is fakemx.net and why are they temp failing me? September 26th, 2012, by admin
In this post, we discuss what fakemx.net is, and why it’s generating temporary delivery failure notices in your mail server logs.
Why is Yahoo! temp failing my mail? September 25th, 2012, by admin
In this article, we explain why Yahoo! sometimes temporarily fails connections to its mail servers with the error: “421 4.7.0 [TS01] Messages from 126.96.36.199 temporarily deferred due to user complaints – 188.8.131.52; see http://postmaster.yahoo.com/421-ts01.html”.
Why did I get “521 5.2.1 : (CON:B1) http://postmaster.info.aol.com/errors/554conb1.html?” September 24th, 2012, by admin
In the first of a series of blog posts where we attempt to de-mystify the most common SMTP error codes, today we discuss the most popular error response from AOL: “521 5.2.1 : (CON:B1) http://postmaster.info.aol.com/errors/554conb1.html”.
Most popular SMTP responses – updated for August 2012 August 31st, 2012, by admin
A summary of the top-50 most popular SMTP error responses, as collected at a major web hosting provider.